[mythtv] Slave backend using different encodings specs

[Thor Johnson]

>> In other words, the profile field in the record table represents,
>> say 0=Default, 1=(same as) LiveTV, 2=Best quality, 3=Save Disk
>> Space, etc. Another table could then associate these with
>> specific codecparams for a class of cards. For most people
>> with one tuner, dual equivalent tuners, multiple backends with
>> similar resources, they would only need one class and profile
>> 0 (Default) is associated with codecparams 0. They would only
>> need to enter these once, as we do now, rather than per host.
>>
>> If they added an MJPEG or future HDTV, DVB, or hardware mpeg2
>> card they could add a new class for these cards so that Default
>> (0) is associated with codecparams 4, LiveTV (1) with params 5
>> and so on. Any number of card classes could be created and
>> any cardinputid could be associated with any class.

>This is more or less what I was suggesting; I'm not sure that it makes
sense
>to do it in every case, as a complete additional layer of indirection,
>however.  I think that two settings or so would be sufficient, and much
>simpler.  For example, one setting for the default profile for recording,
>and another setting for the default profile for Live TV.  Since we have
>per-host settings, this would also provide for different defaults for
>different systems.  Eventually, perhaps, it will be possible to explicitly
>set the scope of a profile (per-host or global).

>I'm not convinced that the type of capture card is a useful criteria,
except
>in the case of hardware MJPEG.  CPU resources, storage resources, output
>device, and input quality would probably be more significant (in that
>order), don't you think?

How about a field like "CompatCodecParms"  added to the capturecard
table that would indicate which capturecards could perform which codec
settings best.  The indirection is easier to handle, but picking a "Default"
gets harder (maybe... maybe not.).  This would also allow heterogenous
backends (e.g.  slowhost can't handle a mpeg4 bitrate of > 1000).  'Course
until the "recordings" get linked with "codecparms", the user has no
idea what kind of encoding/quality the operation will be performed at...

Thoughts?
-Thor Johnson